protocol/packp: sideband muxer and demuxer (#143)

* format/pakp: sideband demuxer

* format/pakp: sideband muxer

* format/pakp: sideband demuxer and muxer

* protocol/pakp: sideband demuxer and muxer

* documentation and improvements

* improvements

* handle scan errors properly

1 files changed, 39 insertions, 0 deletions

diff --git a/plumbing/protocol/packp/sideband/muxer_test.go b/plumbing/protocol/packp/sideband/muxer_test.go
new file mode 100644
index 0000000..38fc4bd
--- /dev/null
+++ b/plumbing/protocol/packp/sideband/muxer_test.go
@@ -0,0 +1,39 @@
+package sideband
+
+import (
+	"bytes"
+
+	. "gopkg.in/check.v1"
+)
+
+func (s *SidebandSuite) TestMuxerWrite(c *C) {
+	buf := bytes.NewBuffer(nil)
+
+	m := NewMuxer(Sideband, buf)
+
+	n, err := m.Write(bytes.Repeat([]byte{'F'}, (MaxPackedSize-1)*2))
+	c.Assert(err, IsNil)
+	c.Assert(n, Equals, 1998)
+	c.Assert(buf.Len(), Equals, 2008)
+}
+
+func (s *SidebandSuite) TestMuxerWriteChannelMultipleChannels(c *C) {
+	buf := bytes.NewBuffer(nil)
+
+	m := NewMuxer(Sideband, buf)
+
+	n, err := m.WriteChannel(PackData, bytes.Repeat([]byte{'D'}, 4))
+	c.Assert(err, IsNil)
+	c.Assert(n, Equals, 4)
+
+	n, err = m.WriteChannel(ProgressMessage, bytes.Repeat([]byte{'P'}, 4))
+	c.Assert(err, IsNil)
+	c.Assert(n, Equals, 4)
+
+	n, err = m.WriteChannel(PackData, bytes.Repeat([]byte{'D'}, 4))
+	c.Assert(err, IsNil)
+	c.Assert(n, Equals, 4)
+
+	c.Assert(buf.Len(), Equals, 27)
+	c.Assert(buf.String(), Equals, "0009\x01DDDD0009\x02PPPP0009\x01DDDD")
+}